187COLON TARGETED METHACRYLIC ACID COPOLYMERIC NANOPARTICLES FOR IMPROVED ORAL BIOAVAILABILITY OF NISOLDIPINEThe objective of this study was to formulate and evaluate the Nisoldipine nanoparticles to enhance the bioavailability and to avoid or reduce the adverse effects of the drug. The clinical application of Nisoldipine was hindered because of its very low oral bioavailability (3.9 – 8.4%), due to its significant first pass metabolism in the liver and gut. Drug containing Eudragit S100 nanoparticles were prepared by nanoprecipitation method and evaluated for its in vitro characteristics like particle size and size distribution, surface morphology and structural characterization, surface charges, drug content, entrapment efficiency, loading capacity and pH dependent drug release. The interactions between the drug and polymer were investigated by Fourier transform infrared spectroscopy (FTIR) and Differential scanning colorimetry (DSC). The formulated nanoparticles were in uniform shape, narrow size distribution with an average size of about 400 nm. In vitro release of Nisoldipine nanoparticles was found to be pH responsive and is evident for the controlled release of its payload only at colon to increase the bioavailability of Nisoldipine by evading the cytochrome P450 (CYP) induced metabolism in liver and gut wall. The experimental results indicate that Nisoldipine loaded Eudragit S100 nanoparticles have better physicochemical characteristics and can be used as a drug carrier for targeted delivery of Nisoldipine in colon, in order to enhance its oral bioavailability.nepoleanrash@yahoo.comResearch382012Nanoparticles,Nisoldipine,Eudragit S100,NanoprecipitationNepolean R,Narayanan N,Subramaniyan N,Venkateswaran K,Vinoth JThanthai Roever College of Pharmacy, Perambalur, Tamil Nadu, India., Jaya college of Pharmacy, Thirunintravur, Chennai, Tamil Nadu, India.,Anna University, Trichirapalli, Tamil Nadu, India.,Anna University, Trichirapalli, Tamil Nadu, India.,Anna University, Trichirapalli, Tamil Nadu, India.